Sunni Islam is the older of the two major forms of Islam, the other being Shiite Islam. Sunnis accept the first four caliphs elected after Muhammad as legitimate; they believe that the caliph, when existing, must be elected from members of Muhammad’s tribe, the Quraysh. The Shiites believe that Muhammad’s successor should have been Ali, his nephew, adopted son, and son-in-law. They believe that only successors after Ali must be from the Hashimite clan of the Quraysh, particularly direct descendants of Ali. The Sunni get their name from those who follow the sunnah, the practices of Muhammad. Sunnis are estimated to be between 75% and 90% of the world’s 1.6 billion Muslims. The uncertainty derives from the practice of Shiite Muslims living in predominantly Sunni ...